How to get all rows from table using MySQL OUTFILE

I'm using MySQL to output the contents of a database table to a CSV file using the following syntax:

SELECT 'Keyword_1_Frequency', 'Keyword_2_Frequency', 'Keyword_3_Frequency', 
'Keyword_4_Frequency', 'Keyword_5_Frequency', 'Keyword_6_Frequency', 
'Keyword_7_Frequency', 'Keyword_8_Frequency', 'Keyword_9_Frequency', 
'Keyword_10_Frequency', 'Keyword_11_Frequency', 'Keyword_12_Frequency','RSSFeedCategoryDescription'  
UNION (SELECT Keyword_1_Frequency, Keyword_2_Frequency, Keyword_3_Frequency, 
Keyword_4_Frequency, Keyword_5_Frequency, Keyword_6_Frequency, Keyword_7_Frequency, 
Keyword_8_Frequency, Keyword_9_Frequency, Keyword_10_Frequency, Keyword_11_Frequency, 
Keyword_12_Frequency, RSSFeedCategoryDescription   
FROM dm_16_945848_18042011_1303128210855  
INTO OUTFILE 'C:/temp/dm_16_945848_18042011_1303128210855.csv'  
FIELDS TERMINATED BY ','  
LINES TERMINATED BY '\n');

The first SELECT clause is simply to get the headers of the columns as the first 开发者_C百科row of the CSV file.

This query seems to be working but for some maddening reason, it is not extracting all of the rows from the table. For eg, if I have 12 rows in the table, it gets 10.

Can anyone explain why? I can see nothing on the MySQL support pages for this.

Thanks

Mr Morgan.

Probably you have duplicates in your table and UNION eliminates them.

Try replacing UNION with UNION ALL.